(function (doc, win) {
	var docEl = doc.documentElement,
		resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
		recalc = function () {
			var clientWidth = docEl.clientWidth;
			if (!clientWidth) return;
			if (clientWidth >= 750) {
				docEl.style.fontSize = '100px';
			} else {
				docEl.style.fontSize = 100 * (clientWidth / 750) + 'px';
			}
			var html = document.getElementsByTagName('html')[0];
			var settedFs = settingFs = parseInt(100 * (clientWidth / 750));
			var whileCount = 0;
			while (true) {
				var realFs = parseInt(window.getComputedStyle(html).fontSize);
				var delta = realFs - settedFs;
				//不相等
				if (Math.abs(delta) >= 1) {
					if (delta > 0)
						settingFs--;
					else
						settingFs++;
					html.setAttribute('style', 'font-size:' + settingFs + 'px!important');
				} else
					break;
				if (whileCount++ > 100)
					break
			}
		};
	if (!doc.addEventListener) return;
	win.addEventListener(resizeEvt, recalc, false);
	doc.addEventListener('DOMContentLoaded', recalc, false);
})(document, window);